Montgomery waddell



M. WADDBLL.

ELECTRICAL INDICATOR.

(No Model.)

m 0% F 6 ml 1 1 F LAW E O ilir r F u E UNITED STATES PATENT OFFICE.

MONTGOMERY WADDELL, OF NEW YORK, N. Y.

ELECTRICAL INDICATOR.

SPECIFICATION forming part of Letters Patent No. 371,720, dated October18, 1887.

Application filed March 19, 1887. Serial No. 231,555. (No model.)

To all whom it may concern:

Be it known that I, MONTGOMERY WADDELL, of the city of New York, in thecounty and State of New York, have invented a certain new and usefulImprovement in Electrical Indicators, of which the following is aspecification.

My invention relates to an indicator of amount and direction of current,designed especiall y for use in the circuits of electric-light ingsystems, and my object is to provide an indicator which shall beaccurate and delicate in operation, not liable to get out of adjustment,and not affected by the earths magnetism, or by that of dynamoelectricmachines near which it may be placed, and which shall not interpose anyextra resistance in the circuit. My indicator, also,is of simple andcheap construction and of compact form and neat appearance.

The main feature of my invention consists in the providing of a split ordivided conductor, forming part of the circuit whose current is to beindicated, between the divisions of which are pivoted twooppositely-magnetized needles turning together on the same pivotedspindle, and each placed as closely as possible to one division of theconductor. The current passing in the same direction through the twodivisions of the conductor causes the two oppositely-magnetized needlesto tend to turn in the same direction, their tendency being to placethemselves at right angles to the conductor, and the reversal of thecurrent causes them both to turn in the opposite direction.

My invention further consists in various novel devices and combinationsof devices employed by me in accomplishing the abovenamed objects, ashereinafter set forth and claimed.

My invention is illustrated in the annexed drawings, in which- Figure 1is a front elevation of an indicator embodying my invention, and Fig. 2a vertical section of the instrument'on the line a: a: of Fig. 1. a

A and A are two straight conductingbars joined at their ends, so thatthey form side pieces of an oblong frame, from the ends of which extendtaperedsleeved extensions B B,

upon a squared portion between a shoulder, 12, and a nut, c, apermanently-magnetic needle, 1

N S or N S, the two needles being oppositely magnetized, as indicated bythe positions of these letters.

The middle portion of the shaft is enlarged, and this enlarged part dhastwo screw-threaded holes extending through it at right angles to eachother, through one of which passes the screw-threaded rod E and throughthe other the pointer F, which is screw-threaded at its middle part.

Secured in any desired way to the ends of the frame are the arcs G G,which are graduated to form a scale, along which the pointer or indexplays on one side or the other. The scale, as shown, is a thin curvedmetal bar set into blocks H H, of hard rubber or other insulatingmaterial, secured to the ends of the frame. I prefer to soinsulate thescale,though it is not absolutely necessary, since the current whichwill pass through it, if not insulated, is usually immaterial. Moreover,the scale may itself be made of insulating material and secured directlyto the metal of the frame. The instrument thus constructed isinterpolated in the conductor the current on which is designed to bemeasured or indicated. The means which I have shown for this purposeform an additional feature of my invention.

In the tubular extension B is inserted a tapering split sleeve, I,having a screw-threaded end, 6. In this sleeve is placed the end of theconductor K, and then upon the inner end of the sleeve, which extendsinside the frame, is screwed a nut, f, which draws the parts of thesleeve together upon the conductor and draws the whole tightly together.At the other end of the instrument the other part of the severedconductor K K is connected in the same way,

and the two sides A A of the instrument thus form a split or dividedconductor, through the two divisions of which the current of coursepasses in the same direction.

The connecting device just described may evidently be used in othersituations for the purpose of making connections to other forms ofelectrical apparatus orinstruments. After the indicator is thusconnected in the circuit, the needles are so adjusted as to setthemselves parallel with the conductors when there is no currenttherein. This is done by screwing the rod E into or out of the spindle,so that the weight of its downwardly-extending part will hold theneedles in the position desired. By this adjustment the needles can bebrought usually to the right position; but a more delicate adjustment isprovided by also screwing the pointer F into or out of the shaft, so asto bring more or less of its weight on one side or the other. Thus, ifthe position of the instrument is not absolutely true the needles canstill be adjusted to bring them parallel with the conductor. Then, sincethe tendency of a magnetized needle is to set itself at right angles toaconductor in proximity to which it is placed, when current flows in thecircuit the needle N S will turn so as to move the pointer in thedirection of the current, and since the needle N S is oppositelymagnetized and is on the opposite side of a conductor whose current isin the same direction, this needle will turn in the same direction as NS, and the two needles will move together against the weight of the rodE,and the direction and amount of the current will be indicated upon thescale by the pointer. As the current increases or decreases the needlesturn to a greater or less distance from their normal position, sincethey are retracted by the weight of red E, and these variations areshown by the pointer. By the use of the two needles a double effect isproduced, so that the smallest variations of current produce aconsiderable change in the position of the pointer. A reversal of thecurrent causes the needles to move back so that the pointer passesacross the zero-point of the scale and still points in the direction ofthe current,and the amount of the reversed currentand any variationsthereof will be indicated.

Since the ellect on the needles of the current varies inversely with thesquare of the distance, the effect on each needle of the opposite sideof the conductor will be so small as to be inappreciablc, for, asstated, each needle is placed as close as possible to its own conductor.The magnetism of the earth or that of dynamoelectric machines or othermagnetic bodies in the vicinity will have no effect upon the instrument,since it will affect the two needles equally and oppositely.

While indicators such as above described are adapted. for use in anydesired situation, they are especiallyzulapted to be placed in thecircuits leading from the several dynamo-electrio machines of a systemof electrical distribution, since in such systems it sometimes occursthat one machine will take current from the others and run as a motor.Myindicator, however, shows instantly the reversal of the current, nomatter howslight the current may be, and the machine can be at onceregulated to obviate this. Also, when a machine is to be disconnectedfrom the circuit and its current is reduced, as usual, before breakingthe circuit, until it begins to receive current from the line, theindicator shows the gradual re duction of current, and shows alsotheinstant when the current is reversed, so that the machine caninstantly be thrown off. Ihe instrument is also especially adapted to beplaced in the neutral wire of a feeder of a three-wire system.

The instrument shown is intended to be placed in an upright or verticalposition, or substantially so. Such an instrument can, however, be usedin a horizontal position if the rod E is put through the sha'l'tin theother direction, so that it will hang downwardly and oppose the tendencyto movement of the needles.

\Vhat I claim is- 1. In an electrical indicator, the combina tion ofasplit or divided conductor and two oppositely magnetized needles pivotedtogether between the divisions thereof, substantially as set forth.

2. In an electrical indicator, the combina tion ofa split or dividedconductor, two oppositelymagnetized needles pivoted together between thedivisions of said conductor, and a retracting device for said needles,substantially as set forth.

3. In an electrical indicator, the combination of a split or dividedconductor, two oppositely-magnetized needles pivoted together betweenthe divisions of said conductor, and an adj ustablc retracting devicefor said needles, substantially as set forth.

at. In an electrical indicator, the combination of a split or dividedconductor, a turning spindle extending across between the divisions ofsaid conductor, two oppositely-magnetized needles on said spindle, eachsituatcdclose to one ofsaid divisions, and an adj ustablcretracting-weight on said spindle, substantially as set forth.

5. In an electrical indicator, the combina tion of a split or dividedconductor, a spindle extending across between the divisionsofsaidconductor, two oppositcly-magnetized needles on said spindle, eachsituated close to one of said divisions, and a rod passing adjustablythrough said spindle, substantially as set forth.

6. In an electrical indicator, the combination of a split or dividedconductor, a turning spindle extending across between the divisions ofsaid conductor, two oppositely-magnetized needles on said spindle, eachsituated close to one of said divisions,'and a rod and a pointer bothpassing adj ustably through said spindle, substantially as set forth.

7. In an electrical indicator, the combine tion of a frame consisting oftwo straight metal sides joined at their ends and provided with meansfor connecting said frame into a circuit, a turning spindle extendingacross between the sides of said frame, two oppositely-magnetizedneedles on said spindle, and an adjustable retracting-weight and apointer on said spindle, substantially as set forth.

8. lhe combination, with the frame, of the tapered sleeved extensions,the tapered split sleeves adapted to enter said extensions and toreceive the ends of electrical conductors, and the nuts adapted to beplaced upon the ends of said split sleeves, substantially as set forth.

9. In an electrical indicator, the combina-s tion of the split ordivided conductor, the two which said pointer moves, substantially asset forth.

This specification signed and witnessed this 18th day of March, 1887MONTGOMERY WADDELL.

Witnesses:

WM. PELZER, E. O. ROWLAND.

2O turning with said needles, and the scale over 7

